Lightroom CC Helper memory issue

I have a substantial photo library which, for historical reasons, has previously been split between a desktop PC and my MacBook Pro. Lightroom CC seemed like a sensible solution for me. However, the Adobe Lightroom CC helper is making my MacBook Pro feel as slow as the 2009 computer it replaced last year. If I kill the Lightroom CC Helper from Activity Monitor then I get a speedy Mac again. I suspect this is due to its memory use: 10.02 GB. Surely this is not intended!